ML20195H148
| ML20195H148 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 01/07/1988 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8801150238 | |
| Download: ML20195H148 (2) | |
Text
C.
c,.
e DuxE POWER GOMPANY P.O.Ito x 33189
, OHAdOTTE. N.o. 28949 MALH. TUCKER ruutruows wwa; et (704) 373 4834 stuaan roosse -
r January 7, 1988 Document Control Desk
. U ' S. Nuclear Regulatory Consnission Washington, D. C.
20555
Subject:
Catawba Nuclear Station, Unit 1 Docket No. 50-413 Special Report Gentlemen; Pursuant to Technical Specification 3/4.8.1.1.3, please find attached a Special
, Report concerning an invalid failure of diesel generator 1A which took place on November 13, 1987. This failure was initially categorized as an Invalid Test.
The failure was reclassified as an invalid failure upon completion of a review on December 9, 1987.
Very truly yours, g /h r m Hal B. Tucker JGT/1214/sbn Attachment xc:
Dr. J. Nelson Grace, Regional Administrator l
U. S. Nt. clear Regulatory Comission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 i
l Hr. P. K. Van Doorn NRC Resident Inspector i
Catawba Nuclear Station b
8801150238 880107 i
PDR ADOCK 05000413 S
e,
'?b,
SPF.CIAL REPORT CATAWBA' NUCLEAR STATION, UNIT 1 SPECIAL REPORT DIESEL GENERATOR 1A INVALID FAILURE ON NOVEMBER 13, 1987 On November 13, 1987, after completing an 18 month mechanical inspection and overhaul, D/G 1A testing was begun to perform break-in runs.
During this testing, on start number 548, the D/G tripped after one minute due to pneumatic control problems. Subsequent start attempts were all successful, and the post overhaul break-in runs were completed by Duke Power Mechanical Maintenance personnel.
This failure was initially categorized as an Invalid Test.
Unit 1 was in Hooo 6, j
Refueling, at the time of this event.
j Testing was conducted to verify D/G 1A operability after the implementation of a modification during the overhaul and to perform the 18 month Periodic Test.
While conducting the test a failuro to start occurred. Work Request 26135 OPS l
was written to investigate and repair the problem.
Duke power technicians traced tSe problem to pneumatic valve "P-3",
its shuttle valve, pneumatic shutdown board logic element "AND 14", logic element "NOT 18", and miscellaneous air leaks in the system. These components were replaced and the air leaks corrected.
Thirty consecutive starts were performed following overhaul and D/G 1A had no further automatic trips. The D/G was inoperable 62 hours7.175926e-4 days <br />0.0172 hours <br />1.025132e-4 weeks <br />2.3591e-5 months <br /> and 42 minutes (from November 18, at 1311 hours0.0152 days <br />0.364 hours <br />0.00217 weeks <br />4.988355e-4 months <br /> until November 21, at 0353 hours0.00409 days <br />0.0981 hours <br />5.83664e-4 weeks <br />1.343165e-4 months <br />).
The replaced components have several functions.
Pneumatic valve "P-3" and its shuttle valve are used to enable a low-low lube oil pressure trip and reset that trip during start of the D/G.
Logic element "AND 14" is used to enable the non-emergency trips af ter approximately one minute of run time.
Logic element "NOT 1A" is used to accomplish shutdown of the D/G upon receipt of an on-engine trip signal.
This failure was initially categorized as an Invalid Test because it was the first test conducted after repairs were made to the D/G Control Air system.
Further review determined that since no maintenance had been performed on these l
Individual logic components and that the problems had been discovered during the break-in runs, the start attempt constituted an Invalid Failure por Regulatory Guide 1.108.
The f ailure was reclassified as an invalid f ailure upon completion l
of the subject review on December 9, 1987. This was the third failure within the last one hundred starts of Unit 1 D/Gs. Therefore, in accordance with Technical Specification 3/4.8.1.1.2 the testing interval was set at 7-day intervals.
Tne health and safety of the public sere unatfected by this event.
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